Water is synonymous with life. In the Gospel according to John (4:7-15), Jesus likens water to life when he asks the Samaritan woman at Jacob’s well for a drink.

Two parts hydrogen and one part oxygen (H2O), water is the most abundant substance in the human body, accounting for 60% of the body’s weight. A loss of only 5 to 10 percent results in serious dehydration. A 15 to 20 percent loss can be fatal.

Uses of Water for the Body

Water is essential in almost all important bodily functions. It is needed for digestion, absorption, and transport of nutrients, elimination of wastes, regulation of temperature, the building and rebuilding of all body tissues.

It is the base for blood, and secretions such as tears, saliva, gastric fluids, and fluids lubricating organs and joints.

The Amount of Water Intake

How many times have we heard our parents remind us to drink more water? For an adult, six to eight glasses are needed for vital bodily functions. Enough amount of water should be taken to compensate for the amount excreted.

Thirst decreases with age. Thus the general rule is for the elderly to drink more water. Those who exercise should drink additional water, especially if it’s extremely hot and humid, as exercise dulls the sense of thirst.

Drinking more water than needed allows the kidneys to increase the volume of urine. It has a cleansing effect for the kidneys and the bladder.

Drinking more water than the kidneys can handle makes the cells absorb the excess, which has oxygenating and rejuvenating effects.

The Abundance of Water

Scientists estimate that Earth’s oceans, lakes, rivers, ice-fields and other reservoirs hold some 14 000 million cu km (330 million cu miles) of water. Another 8.4 million cu km (200 000 cu miles) are stored underground, and large amounts are in the form of vapor in the atmosphere.

The hydrologic cycle of water on Earth accounts for rainfall and evaporation. Scientists believe that since the first clouds dropped the first rainfall, Earth’s original water supply has barely changed.

The Safety of Water

Although water always engages in a self-purification process, many factors contribute to the degradation of its purity. Perhaps second only to air, water is a major carrier of contaminants and microbes.

Through the discharge of industrial waste, arsenic seeps into underground water supplies. The International Agency for Research on Cancer points to arsenic in water as a risk factor for skin cancer, and tumors of the bladder, kidney, liver, and lungs.

Long-term exposure to high levels of arsenic in drinking water may also cause arrhythmia, blood vessel damage, decreased red-blood-cell production and skin discolorations.

Another common problem is old pipes. Corrosions from old pipes result in lead contamination. Lead can build in the body over time up to dangerous levels, which can be damaging to organs and blood cells.

Ways to Ensure Water Cleanliness

The most widely-used method of water cleansing is adding chlorine to water. Chlorine kills microbes. But this method is not without its drawbacks.

Chlorine can combine with components of organic matter to form chlorinated disinfection by-products (CDBPs). Long-term exposure to one of the most common by-product, trihalomethanes, is a risk factor for colon and bladder cancer.

Many households have resorted to home filter systems. A counter-top pitcher, or a unit set up under the sink, can cost up to $1,000.00.

The NSF International in Ann Arbor, Michigan works closely with the governments of the United States and Canada. It sets water-filtering standards in many areas, pinpointing specific contaminants of concern, and helping consumers determine if they need a water filtering system.

It assists customers to select a filter system, testing the product, and providing a statement on the packaging that lists the contaminants (specific to an area) that the product is certified to remove.

But these methods do not preclude human conscientiousness in making water safe. In fact, to ensure the continuous supply of pristine water for the next generations, we all have a duty and responsibility to contribute our share in the efforts of making water remain pure.